1. Field of the Invention
The present invention pertains to fluid powered motors having a plurality of cylinder/piston pairs. More particularly, the present invention pertains to such motors which use a rotating angled plate to reciprocate the pistons.
2. Description of the Prior Art
Fluid pressure operated motors having a plurality of pistons reciprocating in cylinders arranged around an output shaft and being connected to a wobble plate by means of connecting rods are known in the art. One example of such a motor is illustrated and described in U.S. Pat. No. 3,272,079 to J. H. Bent. The motor there described uses pistons and cylinders which do not rotate relative to the housing of the motor, and uses a driveshaft having an angled end portion. A wobble plate bears against each connecting rod and is joined to the angled end of the main driveshaft by a double row ball bearing assembly. This structure enables transmission and translation of reciprocating piston motion to rotary shaft motion.
Other gas or fluid powered motors, such as compressed air motors, utilize a plurality of pistons operating against angled surfaces according to a predetermined sequence to produce rotary motion from gas pressure and linear piston motion. Commonly, however, prior devices require large amounts of precision machining and large numbers of parts to produce motors having reasonable operating life spans. Applications where expected motor life span is of short duration cannot economically utilize precision along life motors. Also, existing gas or fluid powered motors require manual timing and a break in period before useful operation is achieved. The precision tolerances and clearances normally incorporated in such a gas or fluid powered motor dictates the need for specific design for use with either hot or cold gas, but not both because of differing rates of thermal expansion of the various precision fitted parts. Thus, existing motors of this type are expensive to produce and operate, and must be optimized for a limited range of operating conditions.